Crank case ventilator



. y 3, 1955 T. w. HORN 2,707,460

CRANK CASE VENTILATOR Figled April 13, 1953 2 snee'ts-sheet 1 INVENTOR.THUR/WAN 14 Hoe/V y 3, 1955 v 'T. w. HORN 2,707,460

' CRANK CASE VENTILATOR Filed April 13,1953 2 Sheets-Sheet 2 INVEN'TOR.mug/ 1 4 m 170/? United States Patent CRANK CASE VENTILATOR Thurman W.Horn, Anniston, Ala. Application April 13, 1953, Serial No. 348,517Claims. (Cl. 123-41.86)

This invention relates to a crank case ventilator for internalcombustion engines and has for an object the provision of such aventilator wherein a substantial volume of clean filtered air is forcedinto the crank case at a low pressure to drive out undesirable productsof combustion and unused volatile products liberated within the crankcase, thus preventing condensation of such products therein.

Another object of my invention is to provide a crank case ventilator ofthe character designated which shall continue to force air into thecrank case for a short period olf time after the engine has beenstopped, thus removing the remaining gases therefrom.

A further object of my invention is to provide a crank case ventilatorfor internal combustion engines which is propelled by the air blast fromthe engine cooling fan and in which a substantially constant flow of airis forced into the crank case at both idling and high speeds.

A still further object of my invention is to provide a crank caseventilator of the character designated which shall be simple ofconstruction, economical to manufacture, and one which is adapted foreasy installation on conventional internal combustion engines.

Heretofore in the art to which my invention relates, various means havebeen proposed for ventilating the crank case of internal combustionengines. However, so 1 far as I am aware, none of them have proposedintroducing a substantially constant flow of clean filtered air into thecrank case at low pressure to drive out undesirable volatile productsliberated within the crank case. As is well known, undesirable productsof combustion enter the crank case past the pistons and rings, resultingin carbon and sludge formation that are detrimental to the performanceand life of an engine. Also, when oils are heated to a high temperaturethey tend to vaporize and break up into separate compounds, which if notscavenged or drawn out of the engine, form undesirable deposits. Suchundesirable products cannot be effectively removed by creating a partialvacuum in the crank case due to the fact that air would be drawn inthrough all normal or abnormal openings.

A direct blast from the cooling fan through a filter is not satisfactoryfor the reason that air velocities from the cooling fan varyconsiderably. Accordingly, air filters which would permit passage of airat a low velocity would allow too much air to pass at high velocities,thus blowing usable oil out of the engine. Also, to restrict the flow ofair at high velocities would block low velocity air entirely.

Briefly my invention comprises forcing air into the crank case by meansof a small turbine type blower which is driven by a fan located in thepath of the air blast from the engine cooling fan. The blower draws airinto the crank case through a filter and forces the same at low pressurethrough the crank case and thence out through the regular breather pipe.To remove the undesirable gases from the crank case after the engine hasbeen stopped and to assure that a constant flow of air is 2,707,450Patented May 3, 1955 supplied to the crank case at both high and lowspeeds, a weighted inertia member is provided which causes the blower tocontinue rotation for a short period of time after the engine isstopped.

Apparatus embodying features of my invention is illustrated in theaccompanying drawings forming a part of this application in which:

Fig. l is a side elevational view showing the apparatus mounted on aconventional type internal combustion engine; and,

Fig. 2 is a front elevational view of the apparatus shown in Fig. 1.

Referring now to the drawing for a better understanding of my invention1 show an internal combustion engine indicated generally at lit). Theengine it) is provided with the usual cooling fan 11, breather pipe 12,and oil filler conduit 23. A suitable cap i4 is provided for the oilfiller conduit. Some internal combustion engines are not provided withvertically extending oil filler conduits, the.

oil being introduced through an opening at the top of the engine. Withsuch engines I add the oil filler conduit 13 by mounting the same on theengine in communication with the opening at the top thereof. The oilfiller conduit thus mounted on the engine, is secured in place by anysuitable means such as by a light metal clamp 1'6 which surrounds theconduit 13 and is provided with a suitable opening at the outer endthereof which fits over a valve cover stud l7 and is clamped in place bymeans of a nut 18.

Mounted at the side or" the oil filler conduit 13 and communicatingtherewith is the housing of a small turbine type blower 19. The turbineblower is propelled by a drive shaft 2?. mounted in suitable bearings 22at the forward end of the blower housing. Mounted at the forward end ofthe shaft 21 in position to be propelled by the cooling fan ii is a fan23 having a plurality of blades 24. The fan 23 is held against rotationwith respect to the shaft 21 by means of a set screw 25. The volume ofair introduced into the crank case is predetermined by the size of theturbine blower and the size and pitch of the blades 24. if necessary, astrap 26 may surround the blower housing 19 and be fixedly attached tosome convenient part of the engine to hold the device against shifting.Mounted at the end of the blower housing 19 opposite the fan 23 is anair filter 27.

Eucircling the tips of the blades 24 of the fan 23 is a relatively heavyring 23 which provides sufiicient inertia whereby the fan 23 continuesto rotate for 30 to 60 seconds after the engine stops. As the fan 23continues to rotate, the blower 19 is driven thus continuing forcingclean air into the crank case to remove: the remaining gases therefromand preventing condensation of the gases therein.

Due to the inertia of the fan 23, caused by the ring 28, the blower 19rotates at a substantially constant speed. That is, the speed of the fan23 tends to vary slowly with the changes in air velocity from thecooling fan 11, which velocity changes with extreme rapidity withacceleration and deceleration of automobile engines. Also, the filter 27being mounted at the rear of the blower 19, the air from the cooling fan11 flows past the filtering surface and not directly thereagainst. Asthe blast of air passes the filter at very high engine speeds, a vacuumis created immediately adjacent the filtering surface. Due to theresistance of the filter element to high velocity air passingtherethrough and the vacuum thus built up at high speeds the volume ofair blown into the engine is reduced and the blower is slowed down.Another factor which prevents the blower 19 from increasing its speed inproportion to the increase in speed of the engine cooling fan 11 is thefact that there is an increase in pressure within the crank case causedby the piston action therein.

forcing filtered air through the crank case while the engine stops, theundesirable products of combustion and other volatilegases are removedbefore condensation thereof. The removal of these gases immediatelyafter engine is running and for a short period of time after the theengine stops is very desirable in view of the fact that all motionwithin the engine ceases at that time and the residual gases, beingheavier than air, tend to condense and settle in the oil and on parts ofthe engine thus forming sludge and dilution of the oil. It will also beseen that there are no adjustments to be made, since the air flow ispredetermined by the size of the turbine blower and size and pitch ofthe blades of the fan 23.

While I have shown my invention in but one form it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and

I desire, therefore, that only such limitations shall be placedthereupon as are specifically set forth in the appended claims.

Whatlclaim is:

1. In apparatus for ventilating the crank case of an 5 internalcombustion engine having an oil inlet, a breather pipe and a coolingfan, an air blower mounted on the engine and communicating at its airoutlet with said oil inlet, means filtering the air as it passes throughthe intake of said air blower, and means propelled by the air blast fromthe cooling fan and operatively connected to said air blower forrotating the same while the engine is running and for a short period oftime after the engine is stopped.

2. In apparatus for ventilating the crank case of an internal combustionengine having an oil inlet, a breather pipe and a cooling fan, an airblower mounted on the engine with its outlet in communication with saidoil inlet, a filter at the intake of said blower for filtering the airas it passes therethrough, and a fan driven by the air blast from saidcooling fan and operatively connected to said air blower for driving thesame while the engine is running and for a short period of time afterthe engine is stopped.

3. In apparatus for ventilating the crank case of an internal combustionengine having an oil filler conduit, a breather conduit and a coolingfan, an air blower mounted on said filler conduit with its air outlet incommunication with said filler conduit and with its air intake on theopposite side thereof from the cooling fan, a drive shaft for saidblower, a fan fixedly mounted on said shaft outwardly of said blower inposition to be propelled by the air blast from said cooling fan, and afilter at the intake of said blower for filtering the air as it passestherethrougn.

4. In apparatus for ventilating the crank case of an internal combustionengine having an. oil inlet, a breather conduit and a cooling fan, anair blower mounted on the engine with its intake on the side thereofopposite the cooling fan and communicating at its outlet with said oilinlet, means filtering the air as it passes through the intake of saidair blower, a drive shaft for said blower, an air propelled membermounted non-rotatably on said drive shaft outwardly of said blower inposition to be propelled by the air blast from said cooling fan, and aweighted inertia member on said air propelled member causing rotationthereof for a short period of time after the cooling fan is stopped.

5. In apparatus for ventilating the crank case of an internal combustionengine having an oil inlet, a breather conduit and a cooling fan, an airblower mounted on the engine with its intake on the side thereofopposite the cooling fan and communicating at its outlet with said oilinlet, means filtering the air as it passes through the intake of saidair blower, a drive shaft for said blower, an air propelled fan rigidlymounted on said drive shaft outwardly of said blower in position to bepropelled by the air blast from said cooling fan, and a relatively heavyring secured to and encircling the tips of the blades of the airpropelled fan causing rotation thereof for a short period of time afterthe cooling fan is stopped.

References Cited in the file of this patent UNITED STATES PATENTS2,137,559 Algee Nov. 22, 1938 2,553,894 Calloway May 22, 1951 2,578,576Morris Dec. 11, 19,51 2,656,000 Drinkard Oct. 20, 1953

